Trigger + a light = error?

[Dzon]

So i've recently started my adventure with mapping, i'm currently working on a little map for the clan i'm in and i am having a very strange problem that i could not find any information about. I searched through this forum, searched through google and it turns out nobody knows nothing or nobody's encountered this before, ooor i'm just doing something wrong and making a fool out of myself right now. Anyway, here's what i struggle with:
I created a small underground area that's supposed to have switchable lights so that it can get more moody with a press of a button. Radiant 1.4 has no problems compiling the map until i try to point a trigger to a light. The moment i do that the map turns out fullbright. Here's what the error in the cmd looks like:

If i delete any of the target/targetname keys, the problem disappears, but that leads me nowhere because i really want those switchable lights. At first i thought i have too many lights placed close to each other but then i just deleted the trigger and it worked like a charm (and i also learned that it shouldn't really matter how many lights i've placed, i'm still new to the whole mapping things, excuse me ) 

Another screenshot with a proof of (i think) correctly made button. The button's indeed a func_button, and it's target is light1. Radiant's running with admin privileges, operating on Win10. Any ideas what might be the problem? 

P.S. Excuse my poor english, haven't slept yet.
 

[eezstreet]

Try running GTKRadiant in Administrator mode.

It can't write the file because write access is not allowed to the directory.

[Dzon]

It's running in Admin mode, had no problems compiling before. Now i placed an fx_runner and it doesn't wanna compile the lightmap just like with the trigger, and it's funny because i have already placed fx_runners before and they were working fine o_O
 

Edit: K now i deleted the fx_runners and the models for the torches on my walls and it still doesn't wanna compile the lightmap even though everything's like it was before when it was doing ok.
 

Edit 2: I saved the file on a more open partition. So instead of saving it on C, i saved it on E and it worked like a charm. Thanks for pointing me to the problem, appreciate it. Problem solved.

[Langerd]

Try running GTKRadiant in Administrator mode.

It can't write the file because write access is not allowed to the directory.

Heh strange thing.. For example Modview doesnt work for me if I will not start it as the Administrator. The gray background is full white and when i want to open models it crashes O.o weird..